Answer:
4.5 kilograms of silicon dioxide is required to produce 3.00 kg of SiC.
Explanation:
The balanced equation for the reaction between silicon dioxide and carbon at high temperature is given as:

1 mole silicon dioxide reacts with 3 moles of carbon to give 1 moles of silicon carbide and 2 moles of carbon monoxide.
Mass of SiC = 3.00kg = 3000.00 g
1 kg = 1000 g
Molecular mass of SiC = 40 g/mol
Moles of SiC = 
According to reaction, 1 mole of SiC is produced from 1 mole of silicon dioxide.
Then 75 moles of SiC will be produce from:
of silicon dioxide.
mass of 75 moles of silicon dioxde:

4.5 kilograms of silicon dioxide is required to produce 3.00 kg of SiC.
Answer: Planet A: 76% Nitrogen, 23% Oxygen, 1% Other
Explanation: Hope this helps!
Answer:
False
Explanation:
The density of Interstellar dust is very low,yet it still blocks starlight because. .....the Dust emission nebulae like M42 occur only near star that emit large amount of. ......Hydrogen is the major gas in the interstellar medium.